Up to now, there is known an image display device which is mounted on a vehicle such as an automobile to display images that are obtained by capturing images of a periphery of the vehicle through in-vehicle cameras on a display provided in a cabin. Using this image display device, a driver is able to grasp the situation around the vehicle in near real time.
In the case of installing in-vehicle cameras of an image display device on a vehicle, however, shift occurs between the position of an object image contained in an image that is displayed and the position on the design due to a slight error on the installation of the in-vehicle cameras for the vehicle. To address this problem, for example, Japanese Unexamined Patent Application Publication No. 2007-261463 (Patent Literature 1) discloses that installation parameters (for example, a roll angle, a tilt angle, a pan angle, and the like) for the actual installation of in-vehicle cameras are determined through performing of a calibration process, and an image to be displayed is processed using the installation parameters.
In general, a calibration process is performed in a manner that a user (a worker who sets up an image display device) displays images obtained by performing capturing through in-vehicle cameras in a state where markers of a prescribed shape are disposed on the outside of a vehicle, and designates positions of images of the markers contained in the images.